Menopausal hormone therapy: Characterising users in an Australian national cross-sectional study

Menopausal hormone therapy (MHT) is effective for menopausal symptoms, however, its use is also associated with risks of serious health conditions including breast, ovarian and endometrial cancer, stroke and venous thromboembolism. MHT-related health risks increase with longer durations of use. In Australia, while overall MHT use fell when riskrelated findings were published in 2002, a significant number of women continue using MHT long-term. We aimed to examine socio-demographic, health-related and lifestyle characteristics in relation to post-2002 MHT use, and to compare use for <5 and ≥5 years. Data from 1,561 participants from an Australian, national, cross-sectional survey of women aged 50- 69 in 2013 were analysed. Odds ratios (ORs) were calculated using logistic regression for characteristics related to overall MHT use post-2002 and multinomial logistic regression for associations between MHT duration of use [never/<5 years/≥5 years] and personal characteristics, adjusting for sociodemographic, reproductive, health and lifestyle factors. Post- 2002 MHT use was associated with increasing age (p-trend<0.001), hysterectomy versus no hysterectomy (OR:2.55, 95%CI = 1.85-3.51), bilateral oophorectomy vs no oophorectomy (OR:1.66, 95%CI = 1.09-2.53), and ever- versus never-use of therapies other than MHT for menopausal symptoms (OR:1.93, 95%CI = 1.48-2.57). Women with prior breast cancer (OR:0.35, 95%CI = 0.17-0.74) and with more children (p-trend = 0.034) were less likely than other women to use MHT. Prior hysterectomy was more strongly associated with MHT use for ≥5 years than for <5 years (p = 0.004). Ever-use of non-MHT menopausal therapies was associated with MHT use for <5 years but not with longer-term use (p = 0.004). This study reinforces the need for MHT users and their clinicians to re-evaluate continued MHT use on an ongoing basis.